Automatic slide projector



Ma 'h 9, 1954 R. L. BURLA AUTOMATIC SLIDE PROJECTOR 4 Sheets-Sheet 1Filed June 16, 1950 INVENTOR. AoA/Am 1.60am,

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March 9, 1954 R. BURLA AUTOMATIC SLIDE PROJECTOR 4 Sheets-Sheet 2 FiledJune 16, 1950 R. mM N m w a WA ID A m N a a0 H H P I I H I I LI L I I "aI I I I I I lJ I H I "I I IU 4 Shee ts-Sheer, 3

March 1954 R. L. BURLA AUTOMATIC SLIDE PROJECTOR Filed June 16, 1950 4 XL m R E N m m ml n D a N 0. mum em. 3 n B NW 7% Q H March 9, 1954 BURLA2,671,378

AUTOMATIC SLIDE EROJECTOR Filed June 16, 1950 4 Sheets-Sheet 4 INVENTOR.Ran/Aw A. 50244,

Patented Mar. 9, 1954 UN IT ED Sii ES rant :o-rri AUTDMATIC' SLIDEPROJECTOR Ronald LBufla, Beverly Hills, "Gal'if ass'ignor to The(ladwell Corporation, Beverly Hills, Califl, a corporation of CaliforniaApplication June '16, 1950, Serial No. 168,469

stitute therefor a slide to beexhibited and then subsequently to openthe shutter. The slide changing therefor has required several manualoperations to be performed in proper sequence and hence the successfuloperation of the-exhibitor or projector required the services of askilled operator.

The primary object of this invention is to avoid the necessity ofemployingthe services of a skilled operator of the projector apparatusduring the presentation of an illustrated lecture or during theexhibition of slides.

Another object is'to automatically change the slides in a projector orexhibiting apparatus.

A further object is to enable the slides to be exhibited in rapid orrelatively slow sequence so that the changing thereof may be regulatedto suit the rapidity with which aviewermay desire.

Still another object is to effect the changing of the slides in anorderly manner and without interruption and further to avoid thenecessity of an attendant.

The above and other objects may be attained by employing this inventionwhich embodies among its features, a slide gate mounted to rock towardand away from an aperture through which light is projected, an injectorfor moving a slide from the bottom of a stack of slides and advancing ittoward the slide gate and means connected to the injector and the slidegate for advancing the slide onto the slide gate while the .latter isaway from the aperture.

Other features include an ejector operating across the aperture fordisplacing an exhibited slide and clearing the aperture for thepresentation of another slide thereto and means connected to the ejector.and to the slide gate and injector operating means for operating theejector in timed relation to the movements of the slide gate andinjector.

Still other features include a shutter for intercepting light projectedthrough the aperture and means operating in timed relation to theoperation of the slide gate and the injector and ejector for moving theshutter into opening and closing relation to the aperture.

A further feature includes a prime mover connected to the slide "gate,injector and ejector operating apparatus'for'operating the slide gate,injector and ejector, and means between the prime mower and saidoperating apparatus for changing the speed at which the variousoperations take place.

Still further features include timing means operatively connected to theprime mover for continuous operation during the operation of theprojector for regulating the sequence in which the shutter and the slidegate, ejector and injector move.

In the drawings: Figure 1 isa top-'plan view of a slide projectorembodying the features of this invention, the

case 7 being I omitted,

Figure 2 is a side view-of the projector illustrated in Figure 1,showing the position taken by the various cranks and levers during thechanging of a slide,

Figure 3 is a front end view'of the projector illustrated .in Figure- 4,

Figure 4 is a longitudinal sectional view taken substantially along theline 4-4 of Figure 1,

Figure 5 is a transverse sectional view taken substantially on the line-5---5 of Figure4,

Figure fits a transverse sectional view taken "substantially on the line-6--6 of Figure 7,

Figure 7 is a horizontal sectional view taken substantially along .theline -l-l of Figure 2.

Referring to the drawings in detail a base on Ihed I 8 :hassecuredthereto a lamp house designated generally 12, the front wall 14of which is provided with an aperture It through which light isprojected from a source'of illumination 18 by a system of condensinglenses 20.

interposed within the lamp house [2 between thesource .of illumination[8 andrthe lens system 20.is .a partition wall l5 having an aperture l7therein which aligns withthe lens system 20 and carried by the'wall It:on the .side thereof remote from the source of illumination 18 is a pairof spaced vertical guide members [9 in which is mounted a shutter-to bemore fully hereinafter described. An elongated verticalslot 2| is formedin the lamp house It, the purpose of which will hereinafter appear.

Carried by'th'e wall l4 on the side thereof remote from the lenssystemill is a projectorhousing designated generally .22 comprisingspaced parallel side walls .24 and 26 and carried by and extendingbetween .said side walls adjacent the ends thereof remote from the wallI4 is a housing'28 containing afocusing lens system 30 which alignsaxially with the aperture 16 above mentioned. Formed at the junction ofeach wall 24' 3 and 26 with the wall I4 is a vertically extending guidegroove 32, the purpose of which will hereinafter appear, and formedbetween the wall I4 and the housing 26 is a slide receiving chamber 54.

The tops of the walls 24 and 26 are extended upwardly above the top ofthe focusing lens housing 28 to form guides for the lower end of amagazine 36 containing the slides to be exhibited and the top of thelens housing 28 is substantially flat to form a table 38 upon whichrests the lowermost slide in the magazine 36. Carried by the walls and26 and projecting therefrom in a direction opposite the lamp house I2 isa pair of spaced parallel arms 40 and formed on the inner faces of thearms and extending into the walls 24 and 26 substantially at the levelwith the table are opposed grooves 42 in which slides the injector, tobe more fully hereinafter described. A cover plate 46 is carried by thearms and overlies the injector when the latter is in retracted position,and carried by the cover plate at the end thereof adjacent the table 38is a pair of spaced upstanding tongues 05 forming guides for guiding thelower end of the magazine 36 into position above the table 30.

Carried by the cover plate 44 adjacent the end thereof carrying thetongues 40 is a U-shaped bracket 48 carrying a pivot shaft 50 upon whichlatches 52 are mounted to rock, and carried by the cover plate 44 at theend thereof remote from the tongue 46 are upstanding ears 54. Each latch52 is provided with an arm 56 which moves in an arc above and below theaxis of the pivot pins 50 on the side thereof adjacent the tongues 46and connected to each arm is one end of a retractile coiled spring 58,the opposite end of which is connected to an car 54 so that as an arm 56approaches dead center the spring 56 coupled thereto will be extended.In this way each latch 52 is yieldingly held in open or closed position.Carried by the magazine 36 adjacent the lower end thereof is anoutstanding keeper 60 which as the magazine 36 is placed in positionabove the table 30 engages the arms 56 and rocks the latches 52 on theshaft 50 against the effort of the springs 58 until the arms 56 passdead center at which time the springs exert pull on the arms 56 to causethe latches 52 to exert downward pull on the keeper 60. Obviouslyreverse movement of the magazine 38 will increase the tension of thesprings 58 until the arms 56 pass dead center at which time the springs58 will snap the latches to open position. In this way rapid interchangeof magazines may be had.

Carried by the wall 26 and projecting outwardly therefrom is a pair ofvertically spaced ears 62 which are provided with aligned openings inwhich a manually actuated speed control shaft 64 is mounted to rotate.This shaft extends upwardly beyond the upper edge of the side wall 26and carries at its upper end a thumb wheel 66 by which the shaft 64 maybe turned about its axis. The lower end of the shaft 64 projects belowthe bottom edge of wall 26 and is bent to provide a laterally projectinghook member 60 the purpose of which will hereinafter appear.

Fixed to the bed I0 below the side walls 24 and 26 is a frame designatedgenerally I0 comprising side plates 12 and I4 held in spaced parallelrelation by end plates 16 and I8, and mounted on the bed I0 in outwardlyspaced relation to the side plate I2 is an upstanding pedestal 80. Asimilar upstanding pedestal 82 is fixed to the base I0 outwardly fromthe side plate I4. These pedestals carry adjacent their upper endsoutwardly extending axially aligning pivot pins 84 and 86 respectively,the purpose of which will hereinafter appear.

Mounted in the frame 10 for rotation about a horizontal axis is a driveshaft 88 which projects through the plate I2 and carries adjacent itsouter end a drive wheel 90 which has driving connection with a primemover 92 as by a gear train 94. Fixed to the drive shaft intermediateits ends is drive pinion 96 and a drive gear 98 is fixed to the shaft 86within the frame 70 adjacent the plate I4 thereof.

A driven shaft I00 is mounted in the side plates to rotate about an axiswhich lies parallel to the axis about which rotates the drive shaft 88.This driven shaft I00 projects beyond the side plate 12 and has fixedthereto for rotation therewith a timing gear I02. The opposite end ofthe driven shaft I00 projects through the plate 74 and has mountedthereon for rotation therewith and longitudinal sliding movement thereonan arm I04 carrying a laterally extending clutch pin I06. A crank armI08 is mounted for rotation on the shaft I00 adjacent the extreme outerend thereof and carries an inwardly projecting clutch pin IIO whichrevolves in an arcuate path concentric about the shaft I00 andcorresponds to the path in which the clutch pin I06 revolves. Acompression coil spring I I2 encircles the shaft I00 between the arm I04and the crank arm !08 to normally hold the clutch pin I06 out ofengagement with the clutch pin H0 and thus permit the shaft I00 to turnwithout imparting turning movement to the crank arm I08. Pivotallysupported on the outer side of the side plate I4 as at M4 for movementabout a vertical axis which lies between the shafts 08 and I00 is a triplever H6 which engages the arm I04 adjacent the shaft I00 on the sidethereof remote from the spring I I2 so that when the trip arm is movedoutwardly away from the plate :4 the arm I04 will be moved against theeffort of the spring I I2 and cause the clutch pin I06 to engage theclutch pin IIO so as to cause the crank arm I00 to rotate in unison withthe shaft I00. A trip finger H8 is carried by the trip lever H6 at theend thereof remote from the pivot I I4 and is engaged by the trip camI58 carried by the timing mechanism yet to be described.

Mounted on the shaft I00 Within the frame I0 is a drive gear I20 whichmeshes with a drive pinion 96 which is fixed to the drive shaft 00. Thedrive gear I20 is provided between its axis and its periphery with anopening I24 the purpose of which will hereinafter appear. A drive pinionI26 is mounted on the shaft 60 in spaced relation to the drive gear I20and like the drive gear I20 is rotatable relative to the shaft I00. Thisdrive pinion I26 meshes with a drive gear 98 which is fixed to the driveshaft 88 and like the drive gear H0 is provided intermediate its axisand its periphery with an opening I30. Splined or otherwise mounted onthe shaft I00 for longitudinal sliding movement thereon but rotationtherewith is a clutch collar i32 having an annular groove I34intermediate its ends. This collar I32 is located between the gear I20and the pinion I26 and carried at the end of the collar I32 adjacent thegear I20 is a radial arm i36 carrying an outstanding pin I38 which movesin a path concentric about the shaft I00 and which registers with thepath in which the opening I24 revolves. A similar radial arm I40 iscarried by the collar I32 at the end thereof adjacent the pinion I26 andlike the arm I36 car- :ae'nsvs ries a laterally extending pin I42whichIrevo'lves in a concentric path which'registers with the path ofmovement of the opening 130. It will thus be seen that by shifting thecollar I32 longitudinally on the shaft I60 toward the gear I28, the pinI38 may be entered into the opening I24 so as to cause the shaft torotate in unison with the gear I26 at relatively low speed .and that byshifting the collar $32 in the opposite direction toward the pinion52.5, the pin I49 may be entered into the opening Hill so as to causethe shaft to rotate in unison with the pinion I26 at relatively highspeed.

Entering the groove I35 in the collar I32 are the tines of a fork 554which is carried on'the end of a shift rod M6 which is mounted in thewall it to slide transversely of the frame 16. This shift rod carries atthe end thereof remote from the fork Md an annularly grocvedhead I48 inthe groove of which are received opposite legs of the hook 58. It willthus be seen that by rotating the thumb wheel 65 the shift rod I45 andfork use will be moved transversely of the frame Is to shift the collarI32 and enter one .or the other of the pins IE3 or M2 in theirrespective openings 24 or i310 and thereby decrease or increase thespeed at which the shaft Iilt is driven.

Mounted in the frame it! for rotation about an axis which lies parallelwith the axes of the shafts 8B and Phil is a timing shaft I48 whichprojects through the plate It and carries adjacent its end a drive gearIds which has driving connection with the timing gear Hi2 through themedium of a gear train I52. A cam wheel lad is carried by the shaft I 33on the outside of the frame l3 adjacent the plate 14 and this cam wheelis provided on its periphery with an outstanding cam E55 the purpose ofwhich will hereinafter appear. A trip cam I53 projects laterally fromthe cam wheel and moves in a rotary path which intersects the tripfinger H3 so that when the cam wheel I 3 rotates the trip lever I iswill be moved against the effort of the spring 252 to cause the pin I68to engage the pin I and move the crank arm H38 in unison with the shaftIliii.

Mounteu in suitable brackets I68 carried by the wall I8 which projectrearwardly therefrom on opposite sides of the side Walls E i and 26 is ra transversely extending rock shaft I152 which projects beyond theoutside of the wall 25 and mounted for rocking movement on the rockshaft I6? is a shutter actuating lever I64. One end of the shutteractuating lever Iii i is bifurcated as at I56 mounted for rotation insaid bifurcated end tee of the lever IE is a roller I68 which rides onthe periphery of the cam wheel 55% so that the latter revolves, thelever IE4 will be moved about the axis of the shaft I62 by the cam I56.The opposite end of the lever I54 projects through the slot 2I in thelamp house and is slotted as at I'm to receive a stud I12 carried by ashutter I la which is mounted for vertical sliding movement in the guidemembers I9 carried by the partition wall I5 for opening and closing theaperture II therein. A retractile coiled spring HE is connected at oneend to the lever EM intermediate the rock shaft I62 and the slot Ill andthe opposite end of said spring connected to the wall is above the leverI64 so as to exert upward pull on the slotted end of the lever IE5 andhold the roller 588 in contact with the periphery of the cam wheel I54.It will thus be seen that as the cam wheel I54 revolves "withrthetshaftI48, the shutter :IM will .be reciprocated in the guide members It toopen and close the aperture I! in the wall I5 thus alternatelyinterrupting the light rays emanatingfrom the light source I8 which passthrough the aperture ll.

Mounted for rocking-movement on alaterally extending stud I18 carried bythe wall 26=be1ow the .cover plate M is a V-shaped rock arm designatedgenerally I86 one leg I82 of which extends forwardly ancl upwardly andcarries an inwardly extending finger I84. An injector plate 186 ismounted in the guide grooves 12 in the arms 40 and this injector platecarries on the side thereof adjacent the wall 2% and adjacent the endthereof remote from the wall It a-downwardly extending car It? which isprovided with anelongated vertical slot I33 in'which the finger we .isreceived. It will thus beseen that-as the rock arm I85 is moved aboutits pivot I7 8, the injector plate will be moved across the table 3%.When the injector plate 18% moves tothe right when viewed as in Figureit will be evident that the bottommost slide in the magazine 35 will bemoved rearwardly ofi the :teible 38 and into the chamber 34. Pivotallyconnected as at Ifiil to the arm I92 of the rock arm I8!) is one end ofa link ISM the opposite end of whichtis connected as at I98 to the crankarm I88 at the end thereof remote from theshait see. It will thus beseen that as the crank arm 498 rotates with the shaft It!) the rock armIM will be rocked to cause the injector I86 to reciprocate in its guidegrooves #2.

In order to catch slides delivered into the chamber 34 from the table 38and place them in proper position for projection over the aperture IS inthe wall I4 the rock shaft 162 is provided with slide gate comprising apair'o'f spaced parallel arms I98 which carry spaced parallel leafsprings 26% which form cushions upon. which the slides are caught in thechamber 3 and by which a slide is yieldingly held against the wall It incovering relation to the aperture I '8 therein. A bell crank leverdesignated generally $202 is fixed to the rock shaft I62 adjacent theouter end thereof and one arm 204 of said bell crank lever extendssubstantially hort- .zontally toward the lamp house I2 and hasconnectedthereto one end of a retractile coiled spring 205, the opposite end ofwhich is an'c'hored to the base or bed III. This spring 206 yieldinglyextension 2M having an elongated longitudinal slot 2IB therein. A studZIs projects through the slot 2H3 and is fixed in a link 229 adjacentone end thereof. This link are is rigidly connected at I 96 to the crankarm I08 so as to cause the link 2I2 to reciprocate through a limiteddistance and cause the arm 202 to roc'k'the shaft I62 and open the slidegate formed by the springs 299.

In order to eject a slide from its position before the aperture It inthe wall Is an ejector plate I222 is mounted to slide verticallyadjacent the wall id in the guides 32 and carried by the ejector plate222 adjacent the lower corners thereof are forwardly extending ears 224each of which is provided with an elongated longitudinally extendingslot 226. Extending through the slots 226 in the ears 224 is a cross bar228 and riveted or otherwise secured to the cross bar 228 at the endthereof adjacent the side plate 12 is one end of an arm 230, theopposite end of which is pivotally mounted on the stud 84 carried by thepedestal 80. An ejector actuating lever 232 is riveted or otherwiserigidly secured to the end of the cross bar 228 remote from the arm 230and this lever is pivotally mounted intermediate its ends on the stud 86carried by the pedestal 82. The end of the lever 232 remote from thecross bar 228 is pivotally connected at 234 to the lower end of a link236, the upper end of which is connected to the pivot I90 at thejunction of the arm I92 and the link I04. It will thus be evident thatas the pivot I90 moves downwardly under the influence of the link I64,the link 236 will likewise move downwardly to rock the lever 232 aboutits pivot 86 and thus cause the-ejector 222 to move upwardly in itsguide ways 32.

In operation a magazine 36 containing the slides to be exhibited isplaced on the exhibitor by placing its lower end carrying the keeper 60in place adjacent the tongue 46 so that it engages the arms 56 and movesthe latches 52 against the effort of the springs 50 to cause them toengage the keeper 60 and yieldingly hold the magazine in place. With themagazine in such a position the bottommost slide in the magazine willrest on the table 30 and the device is ready for operation. The primemover 02 is then energized, thus causing the drive shaft 88 to rotatethe drive pinion 96 and the drive gear 98 and cause the gear I20 and I26to rotate at different speeds. Upon turning the thumb wheel 26 in aclockwise direction the clutch collar 32 will be shifted longitudinallyon the shaft I to cause the pin I38 to enter the opening I24 in the gearI and cause the shaft I00 to rotate at slow speed in unison with thegear I20. Turning the thumb wheel 66 in a counterclockwise directionwill cause the pin I38 to be withdrawn from the opening I24 and furthermovement of the thumb wheel 66 in a counterclockwise direction willcause the pin I42 to enter the opening I in the pinion I26 and cause theshaft I00 to rotate at a relatively higher speed. Rotation of the shaftI00 causes the timing shaft I48 to rotate through the medium of the geartrain I52 and causes the cam wheel I54 to revolve. As the cam wheel I54revolves, the roller I68 riding on the periphery thereof is engaged bythe cam I56 to cause the lever I64 to rock about the shaft I62 and movethe shutter I14 in its guide ways to open and close the opening I1 inthe partition wall I4. It is to be noted that the cam I56 is of such ashape that the shutter I14 is gradually moved to open position and soheld for a period of time sufficient to give adequate visibility to theslide being projected and that at the expiration of such period, theshutter rapidly moves to closed position. As the cam wheel I54 rotatesand immediately after the shutter I14 moves to closed position, the tripcam I58 carried by the cam wheel I54 engages the finger II8 on the triplever H5 and moves the trip lever IIS about its pivot H4 against theeffort of the spring II2 so as to shift the arm I04 and the pin I06outwardly. Such outward movement of the pin I06 causes it to engage thepin IIO on the crank arm I08 so as to cause said crank arm I08 to rotatein unison with the shaft I00. The revolution of the crank arm I08 aboutthe axis of the shaft I00 actuates both the slide injector and theejector mechanism as follows: As the end of the crank arm I03 movesdownwardly at the start of its revolution, the pivot connection I96exerts pull on the link I04 to move the link 236 downwardly and rock thelever 232 so as to cause the ejector 222 to move upwardly in its guides32 and push a slide held against the wall I4 by the slide gate springs200 upwardly and clear of the aperture I5 in the wall I4. Simultaneouslywith the downward movement of the link, 236, the rock lever I is movedabout its pivot I18 to move the arm I82 in a clockwise direction andthus cause the injector I86 to advance in its guide grooves 42 acrossthe table 30 and push a slide resting thereon into the chamber 04. Inthe meantime the link 220 will have been moved by the crank arm so thatthe stud 2I3 engages the end of the slot 2I6 in the extension 2I4 of thelink 2I2 to exert push thereon and cause the bell crank 202 to rockagainst the effort of the spring 206 and move the slide gate springs 200away from the wall I4 and into a position to receive the slide projectedinto the chamber 34 by the injector I66. Upon further movement of thecrank arm I08, the link 220 will withdraw the stud 2I3 from contact withthe end wall of the slot 2I6 and permit the film gate to close under theinfluence of the spring 206, and thus move the slide received by theslide gate into position before the aperture I0. Upon further movementof the cam wheel I54 the shutters I14 is moved by the cam I55 to openposition so that light from the source of illumination will be projectedthrough the slide and the picture thereon will be visible on a screenplaced in front of the exhibitor. The various cycles of operation arecontinuously repeated so long as the prime mover 02 remains energized.In this way automatic exhibition of slides may be accomplished and thespeed with which the slides are exhibited may be varied to suit thedesires of the user.

While in the foregoing there has been shown and described the preferredform of this invention, it is to be understood that minor changes in thedetails of construction, combination and arrangement of parts may beresorted to without departing from the spirit and scope of the inventionas claimed.

I claim:

1. In a slide projector of the type having a lamp house having anaperture extending therethrough, a source of illumination and acondensing lens system within said lamp house for proecting a beam oflight through said aperture, a projector housing adjacent the lamphouse, a focusing lens system carried by the rojector housing in spacedrelation to the lamp house and defining with said lamp house a slidereceiving chamber, said focusing lens system aligning with the apertureand the condensing lens system, a magazine rising from the projectorhousing above the focusing lens system to receive a stack of slides,means for moving the bottommost slide from the slide stack andpositioning it before the aperture comprising an injector mounted abovethe focusing lens system for movement horizontally beneath the stack ofslides, a slide gate mounted within the slide receiving chamber to rockabout a horizontal axis below the aperture, a system of interconnectinglevers and links operably connected to the injector and to the slidegate for moving said injector and slide gate in proper sequence to.project a slide from the slide stack onto the slide gate withinthechamber and to'move said slide gate with the slide thereon to aposition before the aperture, a drive shaft, aprime mover for rotatingsaid drive shaft, a crank arm mounted on the drive shaft for independentrotation with relation thereto, said crank arm being operativelyconnected to the system of levers and links for operating the injectorand the slide gate, a cam disk mounted for rotation adjacent the driveshaft, means establishing driving connection between the drive shaft andthe cam disk, a trip cam on the cam disk, and means on the drive shaftand contacting the cam disk for engaging the trip cam to establishdriving connection between the drive shaft and the crank arm.

2. In a slide projector of the type having a lamp house having anaperture extending therethrough, a source of illumination and acondensing lens system within said lamp house for projecting a beam oflight through said aperture, a projector housing adjacent the lamphouse, a focusing lens system carried by the projector housing in spacedrelation to the lamp house and defining with said lamp house a slidereceiving chamber, said focusing lens system aligning with the apertureand the condensing lens system, a magazine rising from the projectorhousing above the focusing lens system to receive a stack of slides,means for interrupting the projection of light through the projector andwhile the light is so interrupted ejecting a previously exhibited slidefrom its position before the aperture and positioning a different slidebefore the aperture, said means compring, a drive shaft mounted torotate below the projector housing, a cam disk mounted to rotateadjacent the drive shaft a trip cam on the side of the cam disk, anactuating cam on the periphery of the cam disk, means establishingdriving connection between the drive shaft and the cam disk, a crank armmounted on the drive shaft to rotate independently with relationthereto, normally disengaged clutch means carried by the drive shaft forestablishing driving connection between the drive shaft and the crankarm, means bearing on the clutch means and extending into the path ofmovement of the trip cam for engaging said clutch means and causing thecrank arm to rotate with the drive shaft, a slide ejector mounted in theslide receiving chamber for moving a slide away from its position beforethe aperture, a slide injector mounted above the focusing lens systemfor moving an unexhibited slide into the chamber, a system of links andlevers connected to the injector and to the ejector and to the crank armfor moving said injector and ejector simultaneously a slide gate mountedthe chamber to rock about a horizontal axis therein, a system of linksand levers connected to the crank arm and to the slide gate for movingthe film gate in timed relation to the movements of the injector and theejector,

shutter mounted in the lamp house for movement therein into and out ofposition between the source of illumination and the condensing lenssystem, and means connected to the shutter engaging the periphery of thecam disk for moving the shutter to open position when enby the actuatingcam on the cam disk.

lion and a condensi: system within said lamp house'for projecting a beamof light through said aperture, a

projector housing adjacent the lamp house, a focusing lens systemcarried by the projector housing in spaced relation to the lamp houseand defining with said lamp house a slide receiving chamber, saidfocusing lens system aligning with the aperture and the condensing lenssystem, a magazine rising from the projector housing above the focusinglens system to receive a stack of slides, means for interrupting theprojection of light through the projector and while the light is sointerrupted ejecting a previously projected slide from its positionbefore the aperture and positioning a different slide before theaperture, said means comprising a drive shaft mounted to rotate belowthe projector housing, a cam disk mounted to rotate adjacent the driveshaft, a trip cam on the side of the cam disk, an actuating cam on theperiphery of the cam disk, means establ shing driving connection betweenthe drive shaft and the cam disk, a crank arm mounted on the drive shaftto rotate independently with relation thereto, normally disengagedclutch means carried by the drive shaft for establishing drivingconnection between the drive shaft and the crank arm, means bearing onthe clutch means and extending into the path of movement of the trip camfor engaging said clutch means and causing the crank arm to rotate withthe draft shaft, a slide ejector mounted in the chamber for moving aslide away from its position before the aperture, a slide injectormounted above the focusing lens system for moving an u exhibited slideinto the chamber, a system of links and levers connected to the injectorand to the ejector and to the crank arm for moving sa i injector andejector simultaneously, a slide gate mounted in the slide receivingchamher to rock about a horizontal axis therein, a systern of links andlevers connected to the crank arm and to the slide gate for moving theslide gate in timed relation to the movements of the injector and theejector, and means engaging the periphery of the cam disk for moving thelight interrupting means to open position when engaged by the actuatingcam on the cam disk, a prime mover and speed changing means establishingdriving connection between the prime mover and the drive shaft.

4. In a slide projector of the type having a lamp house having anaperture extending therethrough, a source of illumination and acondensing lens system within said lamp house for projecting a beam oflight through said aperture, a projector housing adjacent the lamphouse, a focusing lens system carried by the projector housing in spacedrelation to the lamp house and defining with said lamp house a slidereceiving chamber, said focusing lens system aligning with the apertureand the condensing lens system, a magazine rising from the projectorhousing above the focusing lens system to receive a stack of slides,means for interrupting the projection of light through the projector andwhile the light is so interrupted ejecting a previously projected slidefrom its position before the aperture and positioning a different slidebefore the aperture, said means comprising, a drive shaft mounted torotate below the projector housing, a cam disk mounted to rotateadjacent the drive shaft a trip cam on the side of the cam disk, anactuating cam on the periphery of the cam disk, means establishingdriving connection between the drive shaft and the cam disk, a crank armmounted on the drl -'e shaft to rotate independently with relationthereto, normally disengaged clutch means carried by the drive shaft forestablishing driving connection between the drive shaft and the crankarm, means bearing on the clutch means and extending into the path ofmovement of the trip cam for engaging said clutch means and causing thecrank arm to rotate with the draft shaft, a slide ejector mounted in thechambar for moving a slide away from its position before the aperture, aslide injector mounted above the focusing lens system for moving anunexhibited slide into the slide receiving chamber, a system of linksand levers connected to the injector and to the ejector and to the crankarm for moving said injector and ejector simultaneously, a film gatemounted in the chamber to rock about a horizontal axis therein, a systemof links and levers connected to the crank arm and to the film gate formoving the film gate in timed relation to the movements of the injectorand the ejector, a shutter mounted in the lamp house for movementtherein into and out of position between the source of illumination andthe condensing lens system, and means connected 12 to the shutter andengaging the periphery of the cam disk for moving the shutter to openposition when engaged by the actuating cam on the cam disk, a primemover, speed changing means establishing driving connection between theprime mover and the drive shaft, and manually actuated means carried bythe projector housing and connected to the speed changing means toselectively control the speed at which the drive shaft rotates.

RONALD L. BURLA.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 647,530 Schneider Apr. 17, 1900 1,161,660 Guerzoni et al Nov.23, 1915 1,247,608 Alguire Nov. 27, 1917 1,298,417 Stillwaggon Mar. 25,1919 1,869,965 Horowitz Aug. 2, 1932 2,503,239 Antos Apr. 11, 1950

